DE102017109553A1 - COMPRESSOR WITH CONTACT-FREE AND CONTACT SEALS - Google Patents

Abstract

A compressor system is disclosed that includes a compressor and a seal pack that includes a non-contact seal and one or more radial shaft seals. In one embodiment, the non-contact seal is disposed near a high pressure portion of the compressor. The offset of the non-contact seal from a shaft used to drive the compressor allows a quantity of pressure-reduced exit air to pass therethrough. A radial shaft seal is coupled axially behind the non-contact seal on the other side of the compressor to the shaft and aligned to reject further passage of the exit air past the radial shaft seal. An outlet conveys exhaust air to return to the compressor. a supporting radial shaft seal can be used axially behind the first radial shaft seal. Another radial shaft seal is disposed adjacent the support seal and aligned in the other direction to seal lubricant for a bearing.

Description

TECHNICAL AREA

The present invention relates generally to seal compression systems, and more particularly, but not exclusively, to seal compression systems having a combination of contact and non-contact seals.

BACKGROUND

Providing compressor systems with adequate sealing packages is still an area of interest. Some existing systems have various shortcomings with respect to certain applications. Accordingly, there is a need for further contributions to this technology area.

SUMMARY

One embodiment of the present invention is a single compressor with primary and secondary seals. Other embodiments include devices, systems, apparatus, features, methods, and combinations for sealing a compressor and keeping compressor fluid and lubricating fluid separate from each other through a combination of seals. Other embodiments, aspects, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herein.

BRIEF DESCRIPTION OF THE FIGURES

1 discloses a compressor and a sealing system.

2 discloses a compressor with non-contact seal and radial shaft seals.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In order to facilitate understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It is understood, however, that this is not intended to limit the scope of the invention. Any changes and further modifications in the described embodiments and any further applications of the principles of the invention as described herein will be considered as would be considered by those skilled in the art to which the invention pertains.

With reference to 1 is an embodiment of a compression system 50 represented, the one by a wave 52 driven compressor 54 which is around a midline 56 is driven and through a warehouse 58 is supported. The compressor 54 is powered by an engine 60 to turn around the center line 56 driven. A sealing package 62 is between the compressor 54 and the camp 58 to provide sealing of one or both of the compressor 54 and the camp 58 arranged. In one embodiment, the sealing package contains 62 Arrangements to prevent the transport of moisture and / or other fluids / particles / debris from the compressor 54 to the camp 58 as well as lubricant from the bearing 58 to the compressor 54 , Sealing packages of this nature have been used in previous devices.

As shown in the illustrated embodiment, the compressor is 54 as a screw compressor, it being understood, however, that other types of compressors 54 are also considered herein. In general, the compressor can 54 any type of device that generates a pressure increase (static, dynamic and / or total) of a fluid. These embodiments disclosed herein may be used in many different types of applications, such as, but not limited to, an air compressor, refrigerant compressor, air blower, etc. The compressor 54 can take the form of a wet or dry compressor. For example, the compressor 54 in one non-limiting embodiment, a screw compressor with water jet injection.

The warehouse 58 is shown schematically in the illustrated embodiment. In general, the camp can 58 any type of bearing device, including a rolling element bearing, fluid bearing, magnetic bearing and a simple bearing, among potential others. In a single non-limiting example, the bearing 58 be a cylindrical roller bearing. In some non-limiting embodiments, the bearing may be a thrust bearing or radial bearing. Whatever the design, in many applications the bearing itself is lubricated with a bearing lubricant. Such a lubricant can take many forms, such as, but not limited to, a liquid oil lubricant that can be sprayed or sprayed onto the bearing, if any.

The engine 60 can be any type of device that is the compressor 54 Moving force supplies, and can take any forms, such as an electric motor, an internal combustion engine, etc. Although shown schematically, the combustion engine 60 the wave 52 Movement force over any intermediate waves, gears, etc. via the direct connection, in 1 is shown, are fed out.

Referring now to 2 is an embodiment of the compression system 50 discloses the further details of the sealing package 62 contains. The sealing package 62 can be a non-contact seal 64 , a series of radial shaft seals 66 . 68 and 70 as well as the camp 58 contain. Also in 2 shown is a series of passes 72 . 74 and 76 which are constructed as outlets for conveying fluid within the passage to another location serving an outlet purpose. In other additional and / or alternative embodiments, the passages 72 . 74 and 76 being constructed as a passage that conveys fluid to another location but otherwise restrains it within a functional system. Further details of the passageways 72 . 74 and 76 are provided below.

The non-contact seals 64 can be a labyrinth seal, spiral seal, etc. For example, the seal may include any number of protrusions and corrugations, whether periodic or not, and whether systematically arranged or not, that repel the conveyance of fluid therethrough. In some embodiments, the non-contact seal may take the form of a helical groove, while in others it may contain separate peripheral projections that are axially offset from one another. Other embodiments are considered herein. Due to its nature, the non-contact seal may not be able to completely prevent the transfer of all fluid past the seal, but the size, location, and orientation may still prevent a fair amount of fluid from passing through the seal. The non-contact seal 64 can in many ways in the compression system 50 be trained and equipped. For example, the non-contact seal 64 be made of many materials, including brass. It may be formed in almost net shape cast, or it may additionally and / or alternatively be formed by a machining operation. Although not shown for clarity, it will be understood by those skilled in the art that various support structures are, however, suitable for certain elements of the compression system 50 to limit, for example, the non-contact seal 64 to the assembly of the compaction system 50 finish. For example, the non-contact seal 64 a seal, an O-ring or other device to support the sealing of the system included. In one non-limiting embodiment, the seal is 78 , in 2 shown on the non-contact seal 64 shown and used for sealing on the support structure, which (again for clarity) is not shown.

The radial shaft seals 66 . 68 and 70 , sometimes also referred to as lip seals, may be used in applications where material flow from one side of the seal to the other is allowed or at least tolerated, but material flow in the other direction is rejected and undesirable. Uses of such seals could allow retention of fluid / debris on a first side of the seal, but otherwise permit venting from a second side to the first side of the seal during overpressure conditions on the other (among other reasons). Although there are three seals, fewer or additional lip seals can be used.

Such lip seals may include one or more lip sections 80 . 82 . 84 containing projecting tip portions, which along an axial direction of the shaft 52 run. The protruding lip portions may generally include a vertex at the end of opposite sides, with one side thereof near the shaft 52 located and / or touched. The ending can be pointed, dull, or take any shape. The sides leading to the tip portion may, in some embodiments (as in FIG 2 shown) may be straight or may take any shape. One or more parts of the projecting lip portions of the seals 66 . 68 and 70 (such as the sides leading to one end of the seal) generally contact the shaft 52 during operation of the compression system 50 , Such contact can occur over a range of speeds, sometimes very high speeds, with the operation of a compression system 50 are connected, such as speeds that can be used with a screw compressor.

In some embodiments, the lip seals 66 . 68 and 70 relatively rigid sections 86 . 88 and 90 as well as yielding sections 92 . 94 and 96 contain. The rigid sections 86 . 88 and 90 can be used to carry loads and provide attachment interfaces for the seals 66 . 68 and 90 at other sections of the compression system 50 not shown in the figure, and to provide internal support for the yielding sections 92 . 94 and 96 be structured. As shown in the illustrated embodiment, the rigid sections 86 . 88 and 90 to be used, a section of the yielding sections 92 . 94 and 96 sandwiched to anchor these sections to the seal. The yielding sections 92 . 94 and 96 may include the lip portions referred to above.

The terms "rigid" and "compliant" are used herein to simplify the description, they are used in a relative sense between the components they each describe (ie, a component may be considered relatively rigid compared to a component that does more Compliant), and they are not intended to be limiting on context unless otherwise stated.

Although the sealing lips 66 . 68 and 70 shown in the illustrated embodiment, an integrated assembly of yielding sections 92 . 94 and 96 together with support sections 86 . 88 and 90 In some embodiments, the sealing lips may be made predominantly of a single material such that the lip portion is integral with any structural support portion of the lip seal. Regardless, in some additional and / or alternative embodiments, the lip portion may be integral with the structural support portion whether or not each is made of the same material. In those embodiments in which the lip portion is integral with the structural support portion, this one-piece structure may be separate from the shaft and bearing assembly disclosed in U.S. Pat 2 However, this does not have to occur. For example, the lip portion and associated material may be formed on-site after the structural support portion in a manufacturing process separate and independent of the shaft and bearing assembly. When integral with the separate lip portion, the support portion may form an outer surface of the one-piece lip seal (as in FIG 2 shown), or it may be embedded therein. In short, any configuration, method of manufacture and lip sealant composition is considered.

Any of the lip seals 66 . 68 and 70 may be the same in configuration, geometry, size, and material as any of the other seals. However, not all seals must be identical to each other. In some embodiments, the pair is lip seals 66 and 68 identical in this way, while the lip seal 70 differs in at least one of geometry, size and type of material. In yet other additional embodiments, the pair of lip seals 66 and 68 and the bearing-side lip seal 70 be identical to each other (but maybe aligned in different directions). In some embodiments of the present application, at least one of the pair of lip seals 66 and 68 and the bearing-side lip seal 70 differ in one or more of configuration, geometry, size and material type.

Any or all sections of the lip seals 66 . 68 and 70 can be made of many materials. In one non-limiting embodiment, the lip seal (s) may include polytetrafluoroethylene (PTFE) material. Such PTFE material on or as the yielding portions 92 . 94 and 96 to be used. For example, the PTFE material may be used as a coating on a substrate material or form the structure itself (eg, the compliant portion may be made of PTFE material). The PTFE material may form all or only a portion of the lip seals.

The lip seals 66 and 68 may be aligned so that the lip portions in the same direction to the compressor 54 point out. Such alignment can be used to repel fluid that is attached to the non-contact seal 64 has leaked over, in one or more of the passages 74 and 76 penetrates. The lip seal 68 Can be used as support for the lip seal 66 to be used. This can, if fluid from the compressor side of the lip seal 66 The seal trickles past the passage, the passage 74 be used as an indication of whether this has been done, all this while the lip seal 68 preserved their integrity to prevent such leakage through the warehouse 58 to prevent. Monitoring the system in this manner can provide early problem detection before further significant problems arise.

The lip seal 70 is shown oriented in the opposite direction to the other lip seals to prevent / reject lubrication from the bearing 58 in one or more of the passes 76 and 74 penetrates.

The passages 72 . 74 and 76 can be led to any position. In the illustrated embodiment, the passage functions 72 as an outlet for conveying discharge air to a suction side of the compressor 54 , The passage 74 can act as an outlet to atmospheric conditions. The passage 76 can apply lubricant to other sections of the warehouse 58 and / or other sections of a lubrication system. Such passages as used herein may include one or more portions of an annular flow path (conduits), piping, tubing, etc., which together form a passage (such as a drain passage) for conveying a fluid.

As used herein, the terms "front" and "rear" are used for ease of reference and are not intended to be limiting of any particular implementation of the invention. For example, reference to a structure within this application as "behind" another structure may not have any reference to whether the particular structure in any given device would be considered "behind" it. Therefore, the terms are meant to express only a relative spatial relationship, not an absolute relationship.

One aspect of the present application provides an apparatus comprising a rotary shaft coupled to a fluid movement component structured to produce a pressure change in the fluid, a non-contact seal disposed about the rotary shaft and rejecting movement of the fluid therethrough wherein the non-contact seal has an upstream axial side corresponding to a side on which the fluid movement component is disposed and a downstream axial side corresponding to the side opposite to the fluid movement component side, the non-contact seal creating a pressure drop as the fluid flows through an annular space formed between the non-contact seal and the shaft, a primary lip seal which is disposed about the rotary shaft and axially offset on the downstream axial side of the non-contact seal, wherein the primary lips seal has a protruding lip extension turned to point to the downstream axial side of the non-contact seal, a drain structure structured to receive fluid between and in contact with the non-contact seal and the primary lip seal after the fluid has passed through has passed through annular space, wherein the drain is configured to return the fluid to the fluid movement component, and a secondary lip seal, which is arranged around the rotary shaft and the primary lip seal adjacent.

A feature of the present application is that the non-contact seal is a labyrinth seal and that the primary lip seal and the backup lip seal are each made of a material containing PTFE.

Another feature of the present application includes that the vent conveys the fluid from the annular space to a relatively low pressure region of the fluid movement component.

Yet another feature of the present application includes that the secondary lip seal includes a protruding lip that extends toward the primary lip seal, and further includes a bearing assembly that is structured to provide bearing loads for the rotary shaft.

Yet another feature of the present application includes a further lip seal disposed about the rotary shaft and offset from the secondary lip seal, wherein the further lip seal is structured to reject the passage of lubricant from the bearing assembly.

Yet another feature of the present application includes that the further lip seal includes an elongate lip having a tip and defining a non-contact side to the shaft with the tip directed toward the bearing assembly, and further an atmosphere drain in fluid communication with a space between the first and second lip seals secondary lip seal and the other lip seal.

Another feature of the present application further includes a bearing drain in fluid communication with a space between the further lip seal and the bearing assembly structured to carry a lubricant.

Another feature of the present application includes that the primary lip seal, the secondary lip seal and the further lip seal each contain a PTFE material.

Another aspect of the present application provides an apparatus comprising a compressor mounted on a shaft, a non-contact seal disposed at one end of the compressor and circumferentially disposed about the shaft, a bleed passage having a fluid flow path that abuts one side of the non-contact seal against the compressor begins, the drain being structured to carry pressurized exhaust air bypassing the non-contact seal, and a pair of lip seals forming an axial rear boundary of the beginning to the exhaust passage, the axially front boundary the beginning of the discharge passage is formed by the non-contact seal, wherein each of the pair of lip seals having respective lips projecting in the same direction to reject further passage of the pressurized discharge air and to promote the flow of the same into the drain.

A feature of the present application includes that the pair of lip seals in the configuration are identical.

Another feature of the present application includes that the materials from which the pair of lip seals are made contain PTFE.

Yet another feature of the present application includes a lubricated bearing pack disposed axially behind the pair of lip seals.

Yet another feature of the present application further includes a bearing-side lip seal adjacent to the lubricated bearing pack and structured to reject the conveyance of lubricant past the seal and away from the lubricated bearing.

Yet another feature of the present application includes that a lip of the bearing-side lip seal includes a tip and adjacent sides that project toward the lubricated bearing package.

Another feature of the present application further includes a vent disposed between the pair of lip seals and the further lip seal, wherein at least one of the pair of lip seals includes PTFE as a material.

Yet another feature of the present application includes a method comprising rotating a shaft to which a compressor is coupled to pressurize a fluid, the compressor having a relatively low pressure region and a relatively high pressure discharge during operation, thus sealing the shaft with a non-contact seal such that an annular offset is formed between the shaft and the non-contact seal, the annular offset permitting an amount of fluid to pass therethrough with concomitant pressure drop in the fluid, sealing the shaft with a first radial lip seal Discharging the amount of fluid accumulated in the space located between the non-contact seal and the first radial lip seal to the compressor so that the fluid quantity is reintroduced into the compressor and sealing the shaft with a second radial lip A seal disposed in a direction axially away from the compressor on an opposite side of the first radial lip seal.

A feature of the present application includes locating the first radial lip seal adjacent the second radial lip seal, and further including supporting the shaft with a bearing assembly disposed farther than the second radial lip seal in the direction axially away from the compressor.

Another feature of the present application further includes sealing the shaft with a third radial lip seal, and further includes venting a fluid present between the second radial lip seal and the third radial lip seal to the ambient atmosphere.

Yet another feature of the present application includes that the first and second radial lip seals are identical, wherein the bearing assembly includes a lubricant, the third radial lip seal being oriented to reject the passage of lubricant to the second radial lip seal, and further including straightening the tips of the first and second radial lip seals in the direction towards the compressor.

Yet another feature of the present application involves the tips of each of the first and second radial lip seals facing in the direction towards the compressor, the tip of the third radial lip seal facing away from the compressor, and wherein the first, second, and second third lip seal PTFE material included.

Yet another feature of the present invention includes that the first and second radial lip seals are identical, and further includes deflating the bearing assembly.

While the invention has been shown and described in detail in the drawings and the foregoing description, the same is to be regarded as illustrative and not restrictive, it being understood that only the preferred embodiments have been shown and described, and that all changes and modifications that in the nature and scope of the invention, are worth protecting. It should be understood that while the use of the words preferably, preferably, or particularly preferably, as used in the above description indicates that the feature so described is more desirable, it may not be necessary, and embodiments that do not require, are considered to be within the scope of the invention, the scope of protection being defined by the following claims. In reading the claims, it is intended that when words such as "a / e", "at least one" or "at least a section" are used, there is no intention to limit the claim to only one element, if not so specifically stated to the contrary in the claim. When the term "at least one section" and / or "a section" is used, the element may include a section and / or the entire element unless specifically stated to the contrary. In addition, unless otherwise specified or limited, the terms "attached," "connected," "supported," and "coupled" and variations thereof are used broadly and include both direct and indirect mountings, connections, supports, and couplings. Further, "connected" and "coupled" is not limited to physical or mechanical connections or couplings.

Claims (21)

Apparatus comprising: a rotary shaft coupled to a fluid movement component structured to produce a pressure change in the fluid; a non-contact seal disposed about the rotation shaft and structured therethrough for rejecting movement of the fluid therethrough, the non-contact seal having an upstream axial side corresponding to a side on which the fluid movement component is disposed and a downstream axial side; which corresponds to the side opposite to the fluid movement component side, wherein the non-contact seal generates a pressure drop when the fluid flows through an annular space formed between the non-contact seal and the shaft; a primary lip seal disposed about the rotary shaft and axially displaced from the non-contact seal on the downstream axial side, the primary lip seal having a protruding lip extension rotated to face the downstream axial side of the non-contact seal; a drain structure structured to receive fluid that is between and in contact with the non-contact seal and the primary lip seal after the fluid has passed through the annular space, the drain configured to return the fluid to the fluid movement component; and a secondary lip seal disposed about the rotary shaft and adjacent to the primary lip seal. The device of claim 1, wherein the non-contact seal is a labyrinth seal, and wherein the primary lip seal and the backup lip seal are each made of a material containing PTFE. The apparatus of any of claims 1 or 2, wherein the vent conveys the fluid from the annular space to a portion of the fluid movement component at a relatively low pressure. The device of claim 3, wherein the secondary lip seal includes a protruding lip that extends toward the primary lip seal, and further includes a bearing assembly structured to provide bearing loads for the rotary shaft. The device of claim 4, further comprising a further lip seal disposed about the rotary shaft and offset from the secondary lip seal, wherein the further lip seal is structured to reject the passage of lubricant from the bearing assembly. The device of claim 5, wherein the further lip seal includes an elongated lip having a tip defined by a shaft contact side and a non-contact side to the shaft, the tip directed toward the bearing assembly, and further an atmosphere exhaust in fluid communication with a space between the secondary lip seal and the other lip seal. The apparatus of claim 6, further comprising a bearing drain in fluid communication with a space between the further lip seal and the bearing assembly structured to carry a lubricant. The device of claim 7, wherein the primary lip seal, the secondary lip seal and the further lip seal each contain a PTFE material. Apparatus comprising: a compressor attached to a shaft; a non-contact seal disposed at one end of the compressor and circumferentially disposed around the shaft; a bleed passage having a fluid flow path starting at one side of the non-contact seal opposite the compressor, the drain being structured to convey pressurized discharge air bypassing the non-contact seal; and a pair of side-by-side lip seals forming an axial rear boundary of the beginning of the bleed passage, the axially front boundary of the beginning of the bleed passage being formed by the non-contact seal, each of the pair of lip seals having respective lips projecting in the same direction; to reject further passage of the pressurized discharge air and to promote the flow of the same into the drain. The device of claim 9, wherein the pair of lip seals are identical in configuration. The device of claim 10, wherein the materials from which the pair of lip seals are made contain PTFE. The apparatus of any one of claims 9 to 11, further comprising a lubricated bearing pack disposed axially behind the pair of lip seals. The apparatus of claim 12, further comprising a bearing-side lip seal adjacent to the lubricated bearing pack and structured to reject the conveyance of lubricant past the seal and away from the lubricated bearing. The apparatus of claim 13, wherein a lip of the bearing lip seal includes a tip and adjacent sides projecting toward the lubricated bearing pack. The apparatus of claim 14, further comprising a drain disposed between the pair of lip seals and the further lip seal, and wherein at least one of the pair of lip seals includes PTFE as a material. Method, comprising: Rotating a shaft to which a compressor is coupled to pressurize a fluid, the compressor having a relatively low pressure region and a relatively high pressure outlet during operation; sealing the shaft with a non-contact seal such that an annular offset is formed between the shaft and the non-contact seal, the annular offset permitting an amount of fluid to pass therethrough with concomitant pressure drop in the fluid therethrough; Sealing the shaft with a first radial lip seal; Discharging the amount of fluid accumulated in the space located between the non-contact seal and the first radial lip seal to the compressor so that the fluid quantity is reintroduced into the compressor; and Sealing the shaft with a second radial lip seal disposed in a direction axially away from the compressor on an opposite side of the first radial lip seal. The method of claim 16, wherein the first radial lip seal is disposed adjacent the second radial lip seal, and further comprising supporting the shaft with a bearing assembly disposed farther than the second radial lip seal in the direction axially away from the compressor. The method of claim 17, further comprising sealing the shaft with a third radial lip seal, and further comprising venting a fluid present between the second radial lip seal and the third radial lip seal to the ambient atmosphere. The method of claim 18, wherein the first and second radial lip seals are identical, wherein the bearing assembly includes a lubricant, wherein the third radial lip seal is oriented to reject the passage of lubricant to the second radial lip seal, and further comprising aligning the tips of the first and second radial lip seal in the direction toward the compressor. The method of claim 18, wherein the tips of each of the first and second radial lip seals point in the direction toward the compressor, the tip of the third radial lip seal facing away from the compressor, and wherein the first, second, and second third lip seal a PTFE material included. The method of claim 20, wherein the first and second radial lip seals are identical, and further comprising deflating the bearing assembly.

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